In recent years, onset of osteoporosis in late middle age has been considered a problem. Especially, it has been known that bone density in women decreases greatly after menopause, because, due to a change in the hormone balance after the menopause, bone destruction through metabolism becomes predominant over bone production. As compared with men of the same age, women are more likely to suffer osteoporosis.
Further, recently, juvenile girls tend to suffer a condition so-called “preliminary climacteric disturbance,” and we are in a situation where not only people of late middle age but also people of younger age may suffer osteoporosis.
Therefore, people in a wide range of ages desire establishment of techniques for assisting diagnostic imaging, diagnostic forecasting, and treatment plans for osteoporosis.
In view of the above, there has been proposed a method of measuring the bone density of a cancellous bone in diagnosis of osteoporosis performed by use of a medical diagnostic imaging apparatus such as an X-ray CT apparatus. In this measurement method, an average of CT values is used as an index for diagnosing osteoporosis, and is compared with results obtained from a plurality of bone density measurement phantoms so as to indirectly measure bone density (see, for example, Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open (kokai) No. Heisei 11-155852
However, in the aforementioned conventional technique, since the internal structure of bones is not analyzed, an index for diagnosing, for example, the progress of osteoporosis cannot be accurately measured.